Brake cylinders of this type are used, inter alia, in rail vehicles. There, they are frequently used to actuate a brake caliper, with the aid of which brake linings are pressed onto a brake disk.
In pneumatic brake cylinders of this type, pistons are provided which form a pressure space together with the inner wall of the brake cylinder. The gap between the piston and the inner wall of the brake cylinder has to be sealed via a sealing ring, with the result that a corresponding pneumatic pressure can be built up in the pressure space. The sealing ring is usually configured as a separate part and is connected to the piston by a press fit or else is screwed. If the sealing ring is connected to the piston via a press fit, a steel ring is vulcanized into the sealing ring. In order for it to be possible to ensure the press fit, the piston also has to be machined specially at the location of the press fit before the sealing ring is attached. The costs for this piston and for the mounting of the piston are comparatively high.
In the case of reconditioning of the brake cylinder, the sealing ring can be exchanged separately. An exchange of this type of the sealing ring has to take place during reconditioning, since the sealing ring is subjected to wear. Likewise, embrittlement of the sealing ring occurs as a result of ageing. During this reconditioning, the piston is dismantled together with a piston tube which is normally connected fixedly to the piston via a screw connection or weld, and the old sealing ring is removed. A new sealing ring is then mounted and the piston with piston tube is installed into the brake cylinder again. The mounting outlay during the reconditioning of a brake cylinder is therefore relatively high.